This invention relates to motor vehicle suspension components and particularly, to a steering knuckle assembly adapted to support a front axle.
Conventional steering knuckles are typically constructed as one-piece forged or cast units. These integral units provide a wheel bearing carrier, torque arms for supporting a disc type brake caliper, and points of attachment for suspension joints. Although these steering knuckles perform satisfactorily, it is desirable to provide enhanced structural and cost optimization of the steering knuckle assembly structure design. It is particularly desirable to reduce the weight of the steering knuckle assembly since weight reductions in this area provide the advantages of reducing both total vehicle weight and suspension unsprung mass. Overall weight reductions improve performance and fuel efficiency. Reductions in unsprung mass are desired since they are capable of providing significant improvements in vehicle ride and handling. It is a further objective to provide an improved steering knuckle assembly which can be produced at a lower cost than current designs. It is additionally desirable to provide an improved steering knuckle assembly which is adaptable to different motor vehicle applications. Another advantgeous feature is the provision of positive mechanical retention of a wheel bearing assembly within the steering knuckle assembly.
The above desirable improvements in a steering knuckle assembly are provided by this invention. In accordance with the preferred embodiment of this invention, a steering knuckle assembly is described which is formed from two mechanically attached components. A bearing carrier is preferably produced by conventional casting or forging processes and includes the wheel bearing carrier and torque reaction arms for mounting a disc brake caliper assembly. The remaining portion of the steering knuckle assembly is formed by a concave shell-shaped housing preferably manufactured using metal stamping processes. The stamped sheet metal housing may be reinforced with one or more internally disposed plates. Mounting bushings for suspension components such as ball joints, struts and steering links are installed and preferably welded to the stamped housing and reinforcing plates. This composite structure provides a significant weight advantage as compared with conventional designs primarily due to the use of stamped components. Use of such components further reduces total cost due to the relative cost advantage of tooling for stamped metal parts as compared to that for casting and machining operations. The steering knuckle assembly according to this invention is easily adapted to different motor vehicle applications merely by changing the configuration of the stamped housing, enabling the same cast or forged bearing carrier component to be used for various applications. As assembled, the steering knuckle assembly according to a preferred embodiment of this invention mechanically traps the wheel bearing assembly within the steering knuckle. Prior art steering knuckle constructions conventionally employ only interference or press fit engagement of these components. The means for retaining the wheel bearing assembly within the steering knuckle assembly according to this invention is therefore more secure and reliable than that provided by prior art designs.
Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which this invention relates from the subsequent description of the preferred embodiments and the appended claims, taken in conjunction with the accompanying drawings.